We all know what KDE stands for, right? Unless you're new here, you'll know that it stands for the K Desktop Environment. While this certainly covers a large chunk of what KDE stands for, it has increasingly lost its meaning over the past few years. Consequently, the KDE team has decided to 'reposition' the KDE brand.

They are not dropping the K prefix. They just gave different names to the categories (kategories?) of the stuff they release instead of just calling everything just KDE. What you are referring to are the KDE Applications and from the linked article:

Software created by the KDE community is branded on its own under the umbrella brand of KDE. Use of "KDE" in the product name is optional and depending on the context. Especially for applications that are not well known as KDE applications and are not easily identified as such by a "K" prefix in their name, it is recommended to use "KDE" in the product name.